Glenoid bone loss in anatomic total shoulder arthroplasty (aTSA) remains a contentious and difficult clinical issue. Previous research has found that aTSA patients with retroversion, posterior bone loss, and posterior humeral head dislocation have a significant risk of glenoid loosening. A study gives a minimum of two-year follow-up data on an all-polyethylene, biconvex augmented anatomic glenoid component for glenoid retroversion and posterior humeral head subluxation repair. This study is a multi-center, retrospective evaluation of prospectively gathered data from 7 global clinical sites on consecutive patients. aTSA was performed on all patients using the biconvex posterior augmented glenoid (PAG). The inclusion criteria were preoperative computed tomography (CT) scan, minimum 2-years after surgery, pre and minimum 2-year postoperative range of motion assessment, and PROMs. Preoperative CT and XR and postoperative XR were used to determine glenoid classification, glenoid retroversion, and posterior humeral head subluxation. A paired t-test was used to make statistical comparisons between pre-and postoperative results.
During the trial period, 86 of 110 consecutive patients (78% follow-up) met the inclusion criteria and were included in the analysis. The average length of follow-up was 35 ±10 months, with a mean age of 68± 8 (range 48 to 85) years. From pre- to post-stop, range of motion improved statistically in all planes. VAS increased from 5.2 preops to 0.7 postops, SANE increased from 43.2 to 89.5, Constant increased from 41.8 to 76.9, and ASES increased from 49.8 to 86.7 (all p<0.0001).
The average glenoid retroversion decreased from 19.3° to 7.4° (p<0.0001). Posterior subluxation decreased from 69.1 to 53.5%, and posterior decentering decreased from 5.8 to -3.0% (p<0.0001). One patient underwent revision because of a prosthetic joint infection and radiological glenoid laxity. At the final follow-up, 79/86 had a Lazarus score of 0 (no radiolucency found around the peg or keel). This study found that a posterior-augmented all-polyethylene glenoid can correct glenoid retroversion and posterior humeral head dislocation after two years of follow-up. Clinically, both ROM and PROMs showed considerable improvement.